In my opinion, and I'm no expert (52 years old), the best way to lose weight at an older age it to jump start your metabolism to lose weight. So cardio. Walking to start, then walking/jogging, eventually jogging-running. OR spinning/bicycling is excellent as well. Once you get your cardio going, and you've increased your general health and lost most or all of the weight, then you can start lifting again for strength and muscle build up so the fat doesn't return. This has been my plan and it's worked so far. Next I plan on getting into weights again soon.

It's really difficult to be losing weight and building muscle at the same time.